NEWS
TUBELESS MAGNETIC AMPLIFIER DC SUPPLIES
Latest additions to the SORENSEN
line! Sorensen Tubeless Magnetic Amplifier DC Supplies are designed for applications where utmost reliability is r e q u i r e d . The f o u r i n s t r u ments described below cover a w i d e range of require ments; additional instru ments are under develop ment and w i l l shortly be a d d e d to the line.
MODEL MA640
(illustrated above)
MODEL MA65
Input
105-125 VAC, 10, 60/v
Input
105-125 VAC, 10, 60fo
Output
4.5 - 7.7 VDC. adjustable
Output
6 VDC, adjustable ± 1 0 %
Load Range 0-40 amperes
Load Range 0-5 amperes
Ripple
Ripple
1 % maximum
1 % maximum
Regulation ± 1 . 0 % for any combination of line and load conditions Accuracy
Regulation ± 1 . 0 % for any combination of line and load conditions Accuracy
Recovery Time
0.2 seconds under worst conditions
Recovery Time
0.15 seconds under worst conditions
Size
17" wide, 1 2 W high, 15" deep Can be furnished for relay rack mounting. Meters, as illustrated, optional at extra cost.
Size
For relay rack mounting — 1 9 " wide, 514" high, 12" deep A cabinet is available for bench operation. This is an unmetered unit.
SPECIAL UNITS Sorensen is engaged in a heavy program of research and development leading to continuous expansion of its standard line of Magnetic Amplifier DC Supplies. It is accordingly in a favorable position to de velop special magnetic amplifier supplies for use in computer systems or other prod ucts requiring the utmost in reliability. If you have special requirements along these lines you will benefit by faking advantage of Sorensen's experience in this power field. Write or call the Applications Engi neering Department, and your problem will receive prompt attention.
MODEL MA2850 Input
190-230, 3#, 4-wire wye, 60i\j
Output
2 3 - 3 2 VDC, adjustable
Load Range 0-50 amperes Ripple
Recovery Time
0.5 seconds under worst conditions
Size
\6VA" wide, 283/i" high, 15" deep Unit is self contained and mounted on casters. Meters are standard with this unit.
SORENSEN FAIRFIELD
AVENUE
STAMFORD, C O N N .
For further information, circle number 36 Λ on Readers' Service Card, page 57 A
36A
Fluorescence Analysis in Ultraviolet Light. / . A. Radley and Julius Grant. 4th ed. xvi + 560 pages. D. Van Xostrand Co., 250 Fourth Ave., New York, Ν. Υ., 1954. $12.00. Reviewed by CHARLES E. WHITE, University of
Maryland, College Park, Md.
Regulation ± 1 . 0 % for any combination of line and load conditions Accuracy
375
Wachs-Enzyklopadie. L. Ivanovszky. Vol. I. 232 pages. H. Ziolkowsky K.G., Augsburg2, Postfach,Germany, 1954. D M 1 1 .
3 % maximum
WRITE FOR MORE DATA For forthe» information about the Sorensen line of tubeless magnetic DC supplies, and for your copy of the latest Sorensen catalog, write Sorensen & Co., Inc., 375 Fairfield Ave., Stamford, Conn, 'n Europe address inquiries to Sorensen A.G , Gar- . tenstrasse 26, Zurich 2, Switzerland.
cussion of principles of instrumentation more intricate than is often necessary. This ιτΐΆγ be a disadvantage in the use of the book in teaching. In general, the beginning student finds it easier to understand simple schematic diagrams than diagrams of commercial instru ments, the design of which, at any rate, varies periodically. Fundamentals are generally presented in a lucid and simple fashion, but in a few instances the discussion is too brief. For example, the equation for the intensity of emitted light in fluorometry is given without even a qualita tive explanation about its origin. Carefully prepared instructions for 24 experiments are given. The authors point out that "an attempt has been made to select experiments that have a practical value because they deal with actual analyses which are frequently performed." Such a program for lab oratory work has the obvious advantage of impressing the student with the use fulness of instrumental analysis. How ever, this leaves very little time for the experimental verification of the essen tial points of theory, while the student spends too much time on operations (dissolution, precipitation, etc.) which are taught in elementary quantitative analysis. Summarizing, this is a well written book which gives a general view of in strumental analysis from a practical point of view.
This book is a welcome revision of the third edition, which was published in 1939. It follows the same plan as the previous edition and is 136 pages larger. Approximately 3500 references are in cluded. These are listed at the end of each chapter, and in addition to those referred to in the text there is a group of references with a notation as to the contents of the article. These addi tional references prove to be a very valuable adjunct to the text, and with this device the authors are able to in clude much more recent material than would be possible in the body of the text. Since there is so much time lag between the original manuscript and actual publication, this seems to be a good technique. The literature coverANALYTICAL
CHEMISTRY
